Tunnel-kiln



P. A. MEEHAN.

TUNNEL KILN.

APPLICATION HLED DEC? 1919. 1,348,51 1 Patented Aug. 3, 1920.

2 SHEETS-SHEET 1.

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P. A. MEEHAN.

TUNNEL KILN. APPLICATION FILED DEC-5,1919.

1 ,348 ,5 1 1 Patented Aug. 3, 1920.

2 SHEETS-SHEET 2- UNITED STATES PATENT OFFICE.

PAUL A. MEEHAN, OF NEW CASTLE, PENNSYLVANIA, ASSIGNOR TO AMERICAN DRESSLER TUNNEL KILNS, INC., OF NEW YORK, N. Y., A CORPORATION OF NEW YORK.

TUN N EL-KILN.

Specification of Letters Patent.

Patented Aug. 3, 1920.

Application filed December 5, 1919. Serial No. 342,724.

To all whom it may concern:

Be it known that I, PAUL A. MEEHAN, a citizen of the United States, and a resident of New Castle in the county of Lawrence and State of lPennsylvania, have invented certain new and useful Improvements in Tunnel-Kilns, of which the following 1s a specification.

My present invention relates to kilns and particularly to kilns of the tunnel type in which the kiln chamber is heated by combustion chambers disposed longitudinally of the kiln chamber.

The general object of the present invention is to provide a special kiln heating combustion chamber construction and arrangement whereby the overall length of a combustion chamber necessary for effective combustion and the effective utilization of the heat of combustion may be substantially reduced. To accomplish this object I form my combustion chambers internally with two passages which communicate with one another at one end of the combustion chamber and at the opposite end are connected one with air and fuel inlets and the other to an outlet for products of combustion. I thus provide a path for the burning gases which is practically twice as long as the combustion chamber structure. My present invention is of especial utility in a kiln such as that used for baking enamel on goods in which the heating up and cooling zones ordinarily provided in a tunnel kiln are unnecessary, and it is desirable to heat a comparatively short kiln chamber uniformly from one end to the other. My improved combustion chambers are not restricted to use in any particular type of kiln, however, but are adapted for use wherever a relatively short combustion chamber is desirable.

The various features of novelty which characterize my invention are pointed out with particularity in the claims annexed to and forming a part of this specification. For a better understanding of the invention, however, and the advantages possessed by it, reference may be had to the accompanying drawings and descriptive matter in which I have illustrated and described a preferred embodiment of my invention.

Of the drawings:

Figure 1 is a plan view in section of the body portion of a kiln.

Fig. 2 is an elevation the broken line 2-2 of FFI g 3 is a section on the line 33 of Fig. 4 is an illustration showing a modified form of combustion chamber construction, and Fig. 5 is a view taken similarly to Fig. 4 illustrating a second modified form of kiln combustion chamber construction.

In the drawings I have illustrated the use of my invention in a kiln comprising a kiln chamber A proper inclosed by a refractory wall B, and having benches B which are located at opposite sides of a pathway for goods carrying cars F, and each support a ombustion chamber G, the two chambers Gr being of similar construction. The cars have wheels running on track rails E. In the respects just noted the construction is that of the ordinary Dressler type of kiln as shown for example in patents granted to Conrad Dressler #1,023,628 and #1,170,428.

In the kiln specifically illustrated herein, the goods carrying cars are introduced into one end of the kiln chamber proper past a doorway normally closed by a door D, from an antechamber L and pass out of the oppo site end of the kiln chamber proper through a doorway normall closed by a door D into an exit chamber similar to the ante-chain ber C Each combustion chamber G is internally divided into two chambers or passages by a longitudinal partition so that the products of combustion pass through the combustion chamber from one end to the other along one side of the partition and then return to the other side of the partition to an exit port located at the same end of the combustion chamber at which air and fuel inlet ports are located. In the construction shown in Figs. 1, 2 and 3 the longitudinal partition I is formed of a fiat plate or plates of refractory material mounted, on supports 1. The outer Walls of each combustion chamber G are formed, as is usual in Dressler kilns, of sections H of hollow refractor tile having open ended passages H through which the kiln atmosphere flows upwardly across the combustion chambers and is heated in its passage, and then passes downward over the goods, heating the latter and being thereby cooled, thus maintaining a partly in section on it the partition IB,

ravity circulation of the kiln atmosphere.

t one.end of each combustion chamber G, a IIlaSOIlIY end portion J is provided which is forme with an air inlet passage J communicating at its lower end with an air supply conduit J and having a horizontal upper portion opening directly to the chamber portion 9 of the combustion chamber above the partition I. A fuel supply nozzle K leads through the end wall of the kiln into the upper horizontal portion of the air passage J The end member J is also pro- Vided with an outlet passage J leading from the chamber 9 below the partition I to the exit conduit J. The opposite end of the combustion chamber is closed by an end member L of refractory material and the partition I stops short of this end member, as shown in Fig. 2, to thereby establish communication between chamber portions 9 and g Regenerators, recuperators or other suitable apparatus may be employed, when (lesirable, to preheat the air supplied to the combustion chambers through the tunnels J 3 and for utilizing the sensible heat in the products of combustion issuing from the combustion chambers through the passage J and conduit J but I have not illustrated such apparatus as suitable forms of such apparatus are well known and their particular form or construction constitutes no feature of the present invention.

The kiln shown is especially devised for use in baking enamel on bath tubs and for like purposes. The combustionchambers A extend practically the full length of the kiln chamber proper. Combustion is initiated in one of the combustion chambers at one end of the kiln, and at the opposite end of the kiln in the other combustion chamber so that variations in tem eratures lengthwise of one combustion cham er are substantially compensated for under normal operation by vslriations in the other combustion chamber. In the respect just noted the kiln illustrated is like that disclosed and claimed in my co pending application, Serial #342,723 filed of even date herewith.

In the modified form of combustion chamber. illustrated in Fig. 4 the partition IA separating the chambers g and g of the combustion chamber is formed of tile sections similar to those forming the outer walls of the combustion chamber. The ventilating or circulating passages I in the tile forming the partition IA communicate at their ends with the corresponding circulating passages H of the vertically disosed walls of the combustion chamber. To insure a gravity circulation through the circulating passa es in the partition IA, the latter is slight y inclined to the horizontal as shown.

In the modification illustrated in Fig. 5, dividing the two portions 9 and 9 of the combustion chamber, is vertically disposed and is in the form of a platelike body of refractory material having upper and lower edge portions I and I bearing against the adjacent surfaces of the upper and lower walls of the combustion chamber.

In each of the different forms of combustion chamber illustrated, heat is effectively abstracted from each leg of the loop shaped flame path, and the heating effect of the combustion chamber as a whole at any point along its length is a joint function of the temperatures of the two legs of the loop at that point.

It will be apparent to those skilled in the art that the special combustion chamber construction illustrated is simple and effective and that it practically halves the ov'erall length of the kiln section occupied by a combustion chamber having the length of flame path required for the effective combustion of a given amount and kind of gas. At the same time, the amount of heat available for abstraction by the goods per unit length of kiln is substantially increased.

While in accordance with the provisions of the statutes I have illustrated and described the best forms of my invention now known to me, it will be apparent to those skilled in the art that changes may he made in the form of the apparatus disclosed without departing from the spirit of my invention as set forth in the appended claims and that certain features of my invention may 100 sometimes be used to advantage without a corresponding use of other features.

Having now described my invention, what I claim as, new and desire to secure by Letters Patent, is:

'1. A combustion chamber structure for kiln heatin provided at one end with air and fuel in ets and an outlet for products of combustion, and formed internally with two passages or chambers extending longi- 110 tudinally of the structure and communicating, one with said inlets and the other with said outlets at the one end of the structure, and in communication with one another at the opposite end of the structure.

2. A combustion chamber structure for kiln heatin provided at one end with air and fuel in ets and an outlet for roducts of combustion, and formed interna ly with two passages or chambers extending longi- 120 tudinally of the structure and communicatin one with said inlets and the other with sald outlets at the one end of the structure and in communication with one another at the opposite end of the structure, and 125 formed with transversely extending open ended channels in its walls.

3. A combustion chamber structure for kiln heating provided at one end with air and fuel inlets and an outlet for products 130 furl? Pmlm i the 'i the (mi end of the sir inlets, am? the other with cnmniimienting with one another 21% posiie end of the strueinre.

i. .i combustion chzm'ibe Si i fi"' l sling pl'flYl llllLl at one 313 i fuel inlets and an ontiei if minnhiisrion and hm a in and fOT'i:

W Hing" n1) :1 l

n iiiwrnii chnnelmi's aiini mwn rating the interior of ihi: wtriiema'e i chambers or passa eg minim:limiting ihe one end of the su-neture, one with saw inlets, and the other \Vlil'l said outlet and con'nnunieating with one another at he posite end of the structure, said g llil'iiifi formed of tile., having mumm es therein extending {1 m The length of the structure CUHHUHELT at their ends with the FUI'I'GSPUIH 1; saigres in the side Walls oi. the st; onion.

5. In a kiln comprising {L kiln (in: proper and, a combustion rhamher struewrc located in thekiln chamber at the side of a goods receiving space therein and formed with circulating passages for Setting up n grrn'iiy circulation of the kiln atmosphere llpwaml past the combustion ehzinil'ier mil downward through the goods receiving space, the improvements which consist in ii in in other :iinl one smother at one ii1 li provisions at tho opposiie mfor supplying air aunt; passages and for with A M oi' combustion from the other ml szsiei passages. each of said si rui' lures iiai'kiilfj its end with the inlet and outlet c'onnei'ilim'is :uljueent the end of the other strncime not having such connections.

Signed 11*; New Castle in the county of Lawrem-e and Si Me of: Penn, this 3d (lay of. December. A. D. 1919.

PAUL A. MEEHAN. 

